Renaming a SDE Version V10 - VB.net

i was trying to rename a Version after it being used in my program to fetch the differences. But it always gives that the Version is in Use.I am not using the version anywhere else at the same time I could not find how to close the connection.While trying to fetch the difference between 2 versions I was able to get the differences and record them and delete a version. But unable to rename the another version.